Adapter with thin round pins used in Peru?

You don't have to purchase an apple adapter. Your power block is rated for world wide power. You can get a plug adapter at any major retailer. Look in the luggage section.

Have a safe trip. I've seen those adapters at Walmart, Walgreens, Office Max, Office Depot and I'm sure there are other retailers. My only suggestion is to stick with a name you know. For example don't get the noname cheapie off amazon. This is electricity you're dealing with. So Targus, Kensington, Belkin, Samsonite, etc. When I went to England the first time they were a bit harder to get, but are now much more common.

Any electronics that you have, just read the power block. If it says it's good for 100-240 then you're good.